Method of forming siftproof bag closures



Dec. 5, 1944.. R. T. MOORE METHOD OF FORMING SIFTPROOF BAG CLOSURES 2Sheets-Sheet 1 Filed Oct. 51, 1941 INVE N TOR fioya/ T Woo/e ATTPRNEYecu 5, 19440 2 Sheets-Shet 2 Filed Oct. 51, 1941 ATTORNEY Patented Dec.5, 1944 METHOD OF FORMING SIFTPROOF BAG CLOSURES Royal T. Moore,Bnfialo, N. Y., assignor to (Jonsolidated Packaging MachineryCorporation, Buffalo, N. Y., a corporation of New York ApplicationOctober 31, 1941, Serial No. 417,218

4 Claims.

This invention relates to new and useful improvements in bag closingmechanisms generally, and particularly seeks to provide novel sealingmeans for forming and sealing bag tops of the single panel fold type.

Paper bags having top closures of the single panel fold are apt topermit a certain degree of sitting since the line of fold of the toppanel may not be closely formed, thereby providing passageway forsifting of material contained within the bags from the mouths thereof.It has been found that such sifting tendencies can be virtuallyeliminated by more sharply defining the line of fold of the top paneland by providing a short sharply creased marginal return; fold at thebag mouth which is'covered by the top flap and sealed by the adhesive.

Therefore it is an object of this invention to provide a bag closingmachine with means to form a single panel told bag closure having apre-formed sharply creased marginal return fold adjacent thebag mouthand-underlying the top panel in the sealed position.

Another object of the invention is to provide a device of the characterstated which can be used in conjunction with either trimmed or undeviceof the character stated in which the marginal return fold of the bagclosure is first positively formedby the creasing means and thenpositively tucked into closure-forming position by a tucker blade.

another object of the invention is to provide a device of the characterstated which will form an adhesively sealed single panel fold closurefor paper bags.

Anotheroblect of a device of the character stated which is simple indesign, rugged in construction and economi- .cal to manufacture.

with these and other objects in view, the nature of which will becomemore apparent, the

invention will be more fully understood by reference to the drawings,the accompanying detailed description. and the appended claims.

In the drawings: V 1 is a fragmentary vertical transverse sectionshowing the crease forming and initial folding'mechanism; Fig. 2 is anenlarged fragmentary detail view showing the first step of creaseforming 1 the invention is to provide Fig. 3 is a view similar to Fig.2, but showing the parts in disengaged relation and the gripper firmlyholding the marginal return fold;

Fig. 4 is a fragmentary vertical transverse section showing the gluingand shaping mechanism together with the final folding and pressingmechanism;

Fig: 5 is an enlarged detail elevation of a portion of the creasingmechanism shown in Fig. l;

Figs; 6, 7 and 8 diagrammatically illustrate the formation of a closureby the machine; and

Fig. 9 is an enlarged fragmentary detail view showing the manner inwhich the crease forming and initial folding mechanism may be combinedwith end trimming mechanism.

The present invention is directed specifically to improvements inmechanism for creasing, folding and sealing a single rpanel fold bagclosure of the kind formed through the use of a bag closing machine suchas is disclosed in the United States Letters Patent No. 2,175,557,issued to R. N. Cundall on October 10, 1939. Since the subject matter ofthis invention employs driving mechanism similar to those disclosed inthe above referred to patent, it is believed unnecessary to hereinillustrate the entire machine, and reference may be made to the patentreferred to for a clear and complete disclosure of such drivingmechanisms.

For convenience in reference, the machine part of this structure thatare identical with the machine parts of the patented structure are giventhe same reference characters as appear in the patent drawings, and themachine puts included in this invention are designated by referencecharacters extending from in to 31'ihclusive.

The creasing and folding means which are constructed in accordance withthe present invention are-applied to the first operating station asillustarted in Fig. 1 of the drawings. A creasing blade l0: having aV-shaped leading edge H is rigidly secured to the machine frame. A platel2 extending through a slot l2a formed in the creasing [blade l0.

The plate 201 is Irecessed along its edges. to receive the spacedextensions 2 l I of a folding member 2|2 normally maintained in contactwith the lower surfaceof the creasing blade 10. The extensions 2 arefixed to theupper ends of a yoke 2|: pivotally carried at the ends ofthe pivot 20!.

A spring 2|! extends from the yoke to the lower surface of the plate 201and tends to mainthe lower surface of the creasing blade. A bolt 2|5,carried by a rigidly mounted bar 225, extends through an opening in theyoke 2I3 and carries adjustable lock nuts 2 l1 forming an abutmentagainst which the yoke strikes near the end of the forward movement ofthe plate 261. Continued movement of the plate 261 causes the yoke torock against the tension of the spring 2 I4 and thereby causes thefolding member 2|2 to drop downward into its position shown in full linein Fig. 1.

The plate 261 is reciprocated through the medium of a link 2 I6, one endof which is pivotally attached to the rod 263 and the other end of whichis pivotally attached to one arm of a bell crank 2I1' journalled on ashaft I36. The other arm of the bell crank is attached to a pitman 2|8adapted to be reciprocated in opposite directions by cam.and followerconnections generally indicated at 226.

A crease anvil I3 having a crease-receiving groove I4 formed across the.face thereof is rigidly secured to the machine frame and is locatedwith the groove I4 thereof disposed substantially in the vertical planeof the upper crease-forming blade edge II.

A creasing assembly I5 which cooperates with the blade I6 and anvil I3to form spaced parallel oppositely directed creases, is carried by oneend of a swinging arm 23|, the other end of which is pivotally mountedon a cross rod I36. The arm 23| is oscillated through the medium oflink, pitman and toggle connections 232, 233 and 234, respectively, andwhich are in turn driven by cam and follower connections generallyindicated at,

The creasing assembly I5 includes a block I6 having a relatively thinrearwardly extending tongue I1 formed integral therewith and adapted tobe received by the groove l4 of the anvil in crease-forming relation. Arearwardly projecting and transversely extending bar I8, formed integralwiththe block I6, is disposed in spaced relation to the tongue I1 and isprovided with a beveled upper face I6 substantially parallel to theopposing face of the creasing blade I6. should be noted that the upperface of the block I6 and the lower face of the crease blade I6 aredisposed in substantially coplanar relation in the creasing position.

A plate 26 having a beveled rear edge portion 26a overlies the upperface of the mounting block and is pivotally connected thereto adjacentthe arm 23I as indicated at 2|. The plate 26 is constantly urged awayfrom the mounting block by a compression spring 22 carried in a well 23formed in the block, and is limited in its outward is adapted to beoscillated through the medium of a link 29, a bell crank 36, and pitman3|. The pitman is given a movement of reciprocation by cam and followerconnections generally indicated at 36'. Continued movement of the camand follower connections 36', causes the roller 26 to become disengagedfrom the bolt head 25, and consequently the plate 26 is permitted torise under the influence of the spring 22 and release the fold.

The bag is then moved by feed means (not shown) to the gluing, finalfolding, and pressing station as indicated in Fig. 4.

At this station it will be seen that there is a folding and pressingmember 265 mounted across the ends of spaced arms 266 movable inguideways 261. A rod 268 passing through the arms 266-at the rearthereof, extends into slots 266 (indicated in dotted lines) in theguides. The arms 266 are provided with depending cam portions 3| whichare engageable with surfaces 212 of the guides 261 and control thevertical movement of the free end of. the member 265. A bar 213,extending across the arms 266, provides support for a bail 214 to whichis attached a link 215 extending from a bell crank 216 mounted on thecross rod I33. The other arm of the bell crank is connected to a pitman211 which partakes of rectilinear motion through the medium of cam andfollower connections (not shown). It will be readily apparent thatvertical movement of the pitman 211 is translated into horizontalmovement of the member 265, the depending cam portions 3| thereofcausing the member to fold the bag mouth upon the top of the bag beforea rearmost portion of the member comes down to press against theclosure.

The member 265 is provided with a channelshaped upper end 266corresponding to the hooked fingers of a persons hand and slopesdownwardly from the end somewhat after the fashion of the palm of a handand then horizontally to correspond to the heel of a hand. Thechannel-shaped movement by a bolt 24 having a rounded head 25 extendingthrough the plate 26, the spring 22, and the block. After the creasingassembly I5 and the complementary creasing elements I6 and I3 have beenbrought into the crease forming position (see Fig. 2) by the cam andfollower connections 231, and as the respective creasing assemblies arebeing separated as theresult of continued movement of the cam andfollower connections (see Fig. 3), the plate 26 'is forced downwardly bythe action of a pressure roller 26 riding over the rounded head 25 ofthe bolt 24 to thereby forcibly bend the lip of the bag closure as thefiap is folded over and provide the closure with a relatively narrowmarginal return fold 21.

Theroller 26 is carried by one end of an arm 26 pivotally mounted on therod I36 and which portion 236 is preferably provided with a flaringmouth to insure guidance of the previously folded bag mouth into thechannel. As the member 266 moves forward its action in folding andpressing the mouth of the bag against the shoulders of the bag is almostexactly the action of a persons hand performing the same function.

A glue blade 3|6, receiving adhesive through the medium of devices notshown, is mounted on a pivoted bail 3H and carried at the ends or spacedlevers 3|2. The glue blade is resilient and extends angular-1y forwardand downward so as to exert a yielding wiping pressure against theshoulder of the bag as it applies adhesive thereto.

A tucking blade 326 (Fig. 4) carried by resilient fingers mounted on bar3 .extends forward above the glue blade and engages the. folded edge ofthe bag as the glue blade moves inward to insure tucking of the mouth ofthe bag into the fold. The member 266 is provided with fins 26l whichnot only depress the tucking blade to insure a tight fold but preventthe blade from snappin upward when released, thereby protecting theresilient fingers. It should be noted that the end of the tucker blade326 engages the ex- I treme end portion of the prefolded marginalreflap. Fig. 7 shows the bag as it arrives beneath the member 265 withthe glue blade 3"] applying adhesive to the bag shoulder, and the tuckerblade 320 engaging the end portion of the return fold 21. Fig. 8 showsthe final position of the memportion upon itself along a line parallelwith and closely adjacent to the upper edges thereof to provide a narrowreturn fold portion, folding said collapsed upwardly extending mouthportion upon itself along a line parallel to the plane of the top of thecontents and in a direction opposite to the direction of fold of saidreturn fold portion V to thereby bring the line of fold-of said returnportion adjacent the intersection between a her 265 pressingthe closureto effect a tight seal.

It should be noted that the return fold 21 is tucked tightly into thecrease where the closure folds over the bag shoulder and is embedded inadhesive, thereby effecting a well bonded seal.

In Fig. 9 of the drawings there is illustrated a modification of thecreasing means which may be employed when the bag ends are to betrimmed. A stationary shear blade 33 is rigidly secured to the machineframe and is disposed in cooperative relation to a movable male creasingmember 34, the upper edge of which comprises a movable shear edge. Afemale creasing member 35 is carried by the movable arm 23l and isadapted to register with the member 34. A. male creasing member 36 whichis also carried by the arm 23l is disposed below the member 35 and isadapted to register with a stationary female creasing member 31 disposedgenerally below the movable shear 34. Thus it will be apparent that theelements 33 and 34 function to trim the bag ends, and the element 34also. cooperates with the creasing member 35 to form the sharply definedmarginal return fold; and that the members 36 and 31 form the usualintermediate crease.

Thus it will be seen that the herein described invention provides a bagclosing machine with means to form a single panel fold bag closurehaving a sharply creased preformed marginal return fold formed adjacentthe bag mouth and underlying the top panel in sealed position, and whichis simple in design and rugged in construction.

It is of course to be understood that various details of arrangementsand proportions of parts may be modified within the scope of theappended claims.

I claim:

1. In a method of closing a filled bag, the steps of folding and sharplycreasing a marginal portion of the collapsed upwardly extending mouthportion upon itself along a line parallel with and closely adjacent tothe upper edges thereof to provide a narrow return fold portion, foldingsaid collapsed upwardly extending mouth portion upon itself along a lineparallel to the plane of the top of the contents and in a directionopposite to the direction of fold of said return fold portion to therebybring the line of fold of said return portion adjacent the plane of thetop of the contents, then applying pressure to said bag along a linedefined by the intersection of the upstanding taining the return foldfromrestraint.

2. In a method of closing a filled bag, the steps of folding and sharplycreasing a marginal portion of the collapsed upwardly extending mouthshoulder of the bag and said upwardly extending mouth portion applyingadhesive to said shoulder of the bag, then applying pressure to said bagalong a line defined by the intersection of the upstanding portion ofsaid mouth and the top plane of the contents to define a fold line,restraining that end of said folded portion containing said return foldportion against unfolding, folding the entire upstanding portion of saidmouth along said defined fold line, and applying. pressure to press themouth, the adhesive, and said shoulder of the bag together whilereleasing the end containing the return fold from restraint.

3. In a method of closing a filled bag, the steps of trimming. the endof the collapsed mouth portion, folding and sharply creasing a marginalportion of the collapsed upwardly extending mouth portion upon itselfalong a line parallel with and closely adjacent to the upper edgesthereof to provide a narrow return fold portion, folding said collapsedupwardly extending mouth portion upon itself along a line parallel tothe plane of the top of the contents and in a direc tion opposite to thedirection of fold of said return fold portion to thereby bring the lineof fold of said return portion adjacent the plane of the top of thecontents, then applying pressure to said bag along a line defined by theintersection of the upstanding portion of said mouth and the top-planeof the contents to define a fold line, restraining that end of saidfolded portion containing said return fold portion against unfolding,folding the entire upstanding portion of said mouth along said definedfold lin and pressing the mouth against the top of the bag whilereleasing the end containing the return fold from restraint.

4..In a method of closing a filled bag, the steps of trimming the end ofthe collapsed mouth portion, folding and sharply creasing a marginalportion of the collapsed upwardly extending mouth portion upon itselfalong a line parallel with and closely adjacent to the upper edgesthereof to provide a narrow return fold portion, folding said collapsedupwardlyextending mouth portion upon itself along a line parallel to theplane of the top of the contents and in a direction opposite to thedirection of fold of said return fold portion to thereby bring the lineof fold of said return portion adjacent the intersection between ashoulder of the bag and said upwardly extending mouth portion, applyingadhesive to said shoulder of the bag, then applying pressure to said bagalong a line defined by the intersection of the upstanding portion ofsaid mouth and the top plane of the contents to ROYAL T. MOORE.

